Detection of endogenous receptors for carbohydrate ligands in primary and metastatic human renal cell carcinoma.

Frozen sections of primary and metastatic human renal cell carcinoma (RCC) were analyzed for the expression of endogenous binding sites for carbohydrates. Fluorescent neoglycoproteins, carrying chemically linked carbohydrate residues on bovine serum albumin as a carrier protein, were applied to 44 primary tumor specimens. In the majority of specimens, accessible binding sites with specificity for maltose and N-acetylgalactosamine were detected. In specimens of normal kidney no specific binding of carbohydrate ligands was observed under these experimental conditions. Specimens of both the primary tumor and a metastasis were available in 10 cases. When the expression of specific binding sites of primary tumors and metastases was compared, the respective patterns were similar with no clear gain or loss of certain lectins in the metastases. We conclude that binding sites with specificity for maltose and N-acetylgalactosamine are present on human RCC and their corresponding metastases.